Automatic telephone system.



F. SCHDENWOLF.

AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED AUG.3, 1908.

NN\\ W 4 E 5 m w 1 6 1 K F. SCHOENWO-LF.

AUTOMATIC TELEPHONE SYSTEM. APPucAnou man was, 1908.

Patented Jan. 25, 1916.

6 SHEETS-SHEET 2.

F. SCHOENWOLF.

AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED AUG-3| I908.

Patented Jan. 25, 1916.

6 SHEETS-SHEET 3- .F. SCHOENWOLF. AUTOMATIC TELEP.|0NE SYSTEM.

APPLICATION FILED -UG.3, 1908. 1,169,754. Patented Jan. 25, 1916.

6 SHEETS-SHEET 4.

F. SCHOENWOLF.

AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED AUG.3, 190a.

Patented Jan. 25, 1916.

6 SHEETS-SHEET 51 ii i @d @Wyfl @77 EE F. SCHOENWOLF. AUTOMATIC T ELEPHONE SYSTEM.

APPLICATION FILED AUG.3, 1908- 1,169,754. I

Patented Jan. 2 5, 1916.

6 SHEETS-SHEET 6- UNITED STATES PATENT OFFICE.

FEED SCHOENWOLF, OF CHICAGO, ILLINOIS, ASSIGNOR TO KELLOGG SWITC TIBOARD & SUPPLY COMPANY, A CORPORATION OF ILLINOIS.

AUTOMATIC TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Jan. 25, 1916.

T 0 all who it may concern Be it knqvn that I, FRED ScHoErvwoLna citizen of he United States, residing in Chicago, coimty of Cook, and State of Illinois, have invented new and useful Improvements in Automatic Telephone Systems, of which the following is a specification.

My invention relates to a system wherein Selective switches at the exchange are adjusted responsive to currents controlled at the substations, the adjusting impulses being controlled by breaks madein a single conductor. so that the system does not employ, where metallic circuit telephone lines are used, the customary return conductor or ground connection. I am aware that systems of this character have heretofore been proposed and the present invention is dimated to securing improved methods of operations in such systems.

To perform a switching operation at the I exchange corresponding in function to that of the rotary or secondary impulse employed in the systems using a ground conductor, I provide, in association with the switch which is directively adjusted by the substation impulses. an auxiliary following switch, set into motion simultaneously with the first switch. which travels at such speed as to overtake a member adjusted by the directive switch very shortlv after the transmission of the last directive impulse of a set. W'hen such overtaking occurs, circuit changes are produced which result in the operations necessary to render the central ofiice apparatus ready to recei e a succeeding set of digit impulses. The indicated method of operation is employed not only in connection with the selectors of the system to initiate the travel for selecting an idle trunk out of a previously selected group, but is also emploved in connection with the connector to shift the wire, transmitting the directive impulses, from its primary connection to its secondary connection at the proper time, and also to transmit the imulse for operating the test relay to test the called for line after the connector has been fully adjusted.

Other more specific features of novelty will be referred to in connection ,with the description of the drawings, and the scope ofthe inventionwill be more particularly pointed out in the appended claims.

Parts 1, 2, 3 and 4 of Figure 1 are to be switches; and Fig. 8 is a detail of the wipersupporting means employed when the mech anism of Fig. 3 is used for a secondary switch.

The diagram of Fig. 1 shows a circuit of the mechanism required to nection from a calling line to a called line in a ten thousand system. Assuming an eX- change of ten thousand lines, said lines as calling lines are preferably divided into groups of one hundred lines each, and each 7 line has multiple terminals 9, 10, 11, appearing in the banks of, say, ten line selectors D, thus making, for the ten thousand lines. one thousand line selectors in all. Said multiple contact sets 9, of the group are preferably divided into ten subgroups of ten contact sets each at the line selectors, and the operation of the line selector I), when set in motion, is first to seek out the sub-group containing the con- 8 tact set of the calling line and then to seek out the individual contact set from the sub group. In the illustrated system, each line selectrr includes a set of primary wipers 29, 30, 31, arranged to be driven by an armature-actuated pawl of primary magnet PM. Although less are shown, the primary wipers have before them ten sets of terminals, each set comprising a contact 33, 34, 35 and 'firtifi The contacts 33, 34, 35 of each set extend to connection with a secondary wiper set a, (1 a, or b, b 5 etc., there being a separate set of wipers adapted to sweep over the multiple line terminals of each sub-group of ten 100 lines. The fourth contact 36 of each setis multipled and extends to the normal contact of the armature of the groupaelay GR of the appropriate sub-group, there being Figs. '2 and 3 are, respectively, 60

establish a con- 10 and 11 of the lines 30 32, all fastened to a primary shaft p, 9

such a relay GR for eaclr sub-group connectcd to a common conductor 23 which has ten branches, one to each line relay of its sub-group. The group contacts 36 of a subgroup and the individual contacts 9, 10, 11 in the sub-group, are normally unselectable. Each line has a line relay LR which is operated when the receiver is removed at the substationand is then effective to cause circuit changes whereby its sub-groups contacts 36 are rendered selectable at the line selectors and also the individual contact sets of the line. Furthermore, the operated line relay influences the masters\vitcl1 mechanism C to start into operation an idle line selector D which will seek out the sub-group and then the terminals of the calling line.

Each line selector D has connected to it by means of the wires L, L, 61, 62, 63, 64, a first selector E, so that there will be one thousand first selectors E for the ten thousand lines. The function of the line selector is thus to seek out the calling line and so connect its associated first selector therewith so that impulses transmitted from the calling station may adjust the first selector to select a group of mult le terminals connected to second seleears of the Wanted thousand. After this, in the process of establishing connection, the second selector will be adjusted responsive to substation impulses to select a group of connectors assigned for connections to the wanted hundreds of the previously selected thousand, whereafter the second selector will automatically select terminals of an idle connector of the group. As called lines, the lines also have their multiple called terminals 6,

7, 8, grouped together by hundreds, the lines having directory numbers of the same hundreds value constituting a. group. The multiple called terminals are preferably divided into ten sub-groups of ten contact sets each and are multipled at the banks of, say, ten connectors, the lines of like tens value in the hundred constituting a sub-group. The calling line. having obtained access to a connectcr for the required hundred in the manner previously outlined, will transmit the proper impulses to cause the selector to select the tens group of the called line, whereafter the connector will be adjusted to select the individual contact set. After this, the called line will be tested and, if found idle, its bell will be automatically rung. If busy, a busy signal will be transmitted to the calling subscriber and he will replace his receiver to restore thecentral ofliee mechanism.

The first selector E, the second selector F and the connector Ur, like the selector D, are provided with a primary magnet PM having an armature controlled pawl to rotime the respective primary shaft 79 which carries the primary wipers. In the case of the first selector E. the primary wipers 97,

98, 99 have before them ten sets of contacts 100, 101, 102 (although less are shown) and each such contact set will extend to connection witha different set of wipers c. c, or (1", (l (l and each such set of wipers will have before it the multiple contact sets of second selector F for a different. thousand. The primary wipers 9T, 98, 99 are first adjusted to select the contacts 100, 101, 102, connected vwith the wiper sets for the wanted thousand. The wiper sets for all the thousands are mounted upon the one shaft 8 and actuations then caused of secondary magnet SM will rotate all the wiper sets step by step until the private wiper of that set,

rendered live by being selected by the primary wipers, encounters the multiple contact sets 103, 104, 105 of an idle second selector. In the second selector F, the same method of selection is employed, the primary wipers 128, 129, 130, mounted upon primary shaft being first rotated by primary magnet PM to select the setof secondary wipers of the proper group, whereafter all the sets of secondary wipers e, f, etc., of which there will be ten in all, will be rotated by actuations of secondary magnet SM until the private wiper F, or which ever one has been rendered live by being selected by wiper 130, reaches a set of multiple contacts 131, 135, 136, pertaining to an idle connector. At the connectors G, the selection of the sub-group of the called line is effected by actuations of primary magnet PM rotating the primary wipers 207, 208, 209, mounted upon shaft p, to select the contact set 210, 211, 212, connected to the wiper set assigned to the sub-group of contacts of the proper tens value, whereafter all the wiper sets 9, k. etc.,of which there will be ten, are simultaneously rotatedby secondary magnet SM until the contact set 6, 7, 8 of the called line is reached.

Each selector, whether D,'E, F or G, includes, in addition to the wiper mechanism already referred to, a primary otf-normal switch PO having contacts shifted on the first step of the primary wiper, and a secondary off-normal switch S0 having contacts shifted on the first step of the secondary wipers. All the mechanism in Fig. 1 is shown in its normal or resting condition and the shifting of the primary and secondary off-normal switches will effect circuit changes obvious from an inspection of Fig. 1. The talking circuit to be established is throughout indicated by heavy lines. The first selector E has mounted upon the primary shaft 1), in addition to the wipers, an arm 68 insulatingly supporting the spring 09 and its normal and alternate contacts. Fitting loosely about and independently rotatable with respect to shaft p, is a notched disk 67, its notch bedirective impulses magnet 66, greater or less distance.

69 will engage its normal contact and ,the magnet 200 to the ing normally engaged by spring69. The disk 7 is adapted to be rotated step by step in the direction indicated by the arrow by an armature actuatedpawl of magnet 66, said magnet being responsive to the thousands impulses; and when said disk 67 spring 69 rests upon the periphery of the disk. As long as said spring 69 is upon the periphery and so engaging its alternate contact, the primary magnet PM will receive current impulses and will drive the wipers 9T, 98, 99 and the arm 68, which carries the spring 69 and by step in the same direction that disk 67 travels, but at a somewhat slower rate. According as a greater or less number 0 have been transmitted to 67 will have advanced a As soon as the directive impulses cease, and sufiicicnt actuations of magnet PM are caused to bring the spring (39 to a position where it again slips into the notch of disk 67,

the disk y so doing will effect circuit changes resulting inactuations of secondary magnet SM which will step the secondary wipers step by step in a manner previously indicated to select idle contacts. In a similar manner, the bum dreds impulses are transmitted to the magnet 124 of second selector F, which rotates disk 125. whereupon the magnet PM has impulses transmitted to it, moving shaft V, which supports the primary wipers and also the arm 126, carrying circuit changing spring 127 and its contacts, step by step in pursuit of the notch of disk 125. After the transmission of the last hundreds impulse, such pursuit will terminate and the relingagenicnt by spring 127 of the notch in disk 12.) shifts the said. spring to normal, circuit changes being occasioned, resulting in actuations of magnet SM which steps the secondary wipers in search of idle contacts. At the connector G, the magnet 195 is operated by the primary impulses and steps the disk 196 having a notch normally e11- gaged by spring 197. Primary magnet PM immediately begins stepping the primary wipers, and arm 201, supporting spring 197 and its associated contacts, step by step in pursuit of the notch on disk 196. \Vhen the tens impulses cease, the disk of course rests, and when the shaft p reaches the proper adjusted position, spring 197 shifts to normal and causes circuit changes to connect impulse wire L", the magnet 195 then being disconnected. The units impulses are transmitted to magnet 200, which steps disk 201, and the secondary magnet 5M steps the secondary wipers and the arm 203, supporting spring 202 and its contacts, in pursuit of the notch of disk 201. When the units impulse ceases, and the is 0 rotated, the bent extremity of the' its contacts, step said s ringspring 202 thereafter engages the notch, the secondary wipers stop and-the testing impulse is transmitted to test relay TR.

It will be understood that no specific ratio of operation between the speed at which impulses are transmitted to a magnet, as for example 124 at F to rotate the disk, and to the primary magnet PM", need be specifi cally stated. Assuming that each selector has ten groups to select as a maximum, it is only necessary that when the travel of the disk and of the primary shaft is initiated, as long as said disk is being rotated responsive to directive impulses from the substation, it shall keep slightly ahead of the following spring 127. For example. if disk 125 and primary shaft p had each a ratchet wheel for driving them. having the same numbers of teeth, the substation calling device may i i at, say, the rate of sixteen per second. while the interrupter I of actuating magnet PM may be driven at the rate of ten impulses per second.

The remaining circuit connections not heretofore specifically described will be best understood from the following description of the operation. in which it. will be assumed that substation A is that of the calling subscriber and that connection is desired with the line of substation Z, which may be assumed to have the number 2221. In initiating the call, subscriber A removes his receiver, whereupon hook-lever 1 rises and current flows from ground through line relay LR. normal contact 19. S. 3. hook-lever 1, magnet 2, P, normal contact 21 to battery, whereupon armature 15 grounds its branch of wire 23 and group relay GR attracts its armature, removing ground from multiple group contacts 36. The attraction of armature 15, by opening its normal contact, removes the normal ground from private contacts 11 at the line selectors. rendering the contact sets 9, 10, 11 selectable. Armature 16 grounds the multiple private contacts 8 at the connectors. rendering the line busy there. By armature 17, relay LR is disconnected from the line and locked through normal contact 18 and itsbranch of common wire 24 in series with master-switch relay 22. Master-switch C is common to a one hundred line group, and the ten line selectors U for selecting such lines and has a contact set 26-28 for each line selector D before its wipers 27, and the arrangement is such that said wipers normally engage the contact set of an idle line selector. as hereafter more fully explained. The relay 22 is rendered common to by conductor 21 having one hundred branches. one to each line of the group. When relay 22 operates, its attracted armature connects ground through contact 2526, normal contact 40, normal cbntact 55,

the one hundred lines a through relay PR to battery, and said relay, by armature 47, closes circuit from generator G through primary magnet PM to ground. Said primary magnet receives actuations, stepping the primary wipers 29, 30, 31, 32 until wiper 32 engages the multiple group contact 36 of the sub-group of the calling line, since, until this occurs, relay PR will remain operated by current through normal contact 55-55, attracted armature 46, wiper 32 and successive engaged group contacts 36 of sub-groups not having a calling line amongthem, their group relays GR being accordingly deelnergized. When in the present case, wiper 32 engages the second contact 36, the circuit of the relay PR is open at the armature of relay GR and the relay- PR- deenergizes, the retracted armature 47 preventing further actuations of magnet PM.. On the first step of the primary Wipers, the primary off-normal contacts 38, 39 and 40 were shifted to their alternate positions, the opening of contact 40 rendering relay PR solely dependent, for continued energization, upon the circuit traced through wiper 32. The retraction of armature 48 of relay PR closes circuit from ground through contact 3941, secondary relay SR to battery, and said relay is energized, its armature 51 closing circuit from generator G through secondary magnet SM to ground. As long as relay SR remains operated, magnet SM receives actuations, stepping the wiper sets a, 6, etc, step by step over their respective sub-groups of contact sets 9, 10, 11. Such stepping will continue until the private wiper a now connected through contact 35- -31 and alternate contact 52 with relay SR. engages the private contact 11 of the calling line, since successive contacts 11 of non-calling lines will be grounded, thus holdin relay SR energizedover successive locking circuits. When the contact 11 of the calling line is engaged by Wiper a the absence of ground found there will denergize secondary relay SR and its armatures will be retracted, preventing further actuations of secondary magnet.

SM. The secondary off-normal SO contacts 41 to. 45 inclusive were all shifted on the first step of secondary shafts, the shifting of contact 41 rendering secondary relay SR solely dependent for its energization upon the circuit traced to wiper a Because of the shifting of contact 42, the retraction of armature 52 connects ground through contact 31-35 and through wiper to private multiples 11 of the calling line. rendering them again unselectable. At this time, circuit may be traced from battery at C, relay R, contact 2728. normal contacts 52, contact 42 to ground, whereby master-switch relay R energizes and closes circuit through motor-magnet M which receives generator impulses, stepping wipers 25, 27 over the .mature 16 connects the contact sets 26, 28, in search of a set pertaining to an idle line selector D. The contacts 28 of line selectors which are not at normal will be grounded so that successive locking circuits for relay R \tll be established with the travel of wiper 25, 27, until the contact 28 of an idle line selector is encountered, when its ungrounded condition will occasion the deenergization of relay R and the stopping of master-switch C, whose wipers will then rest engaging the contact sets of an idle line selector ready for starting it when another call is initiated. As soon as relay SR energized to initiate travel of the secondary wipers, wires L and L were conductively connected through alternate contact 60, whereupon relays PR and SR of first selector E (which, together with battery B, are, through normal contacts at 76 and 75, bridged acrosswires L and L) were energized. When relay SR denergizes,con,- tact 49 closing, establishes a circuit from ground through relay PR, extending over wire L, normal contact at 20, cut-ofl' relay CO to battery, and said relay attracts its armatures, whereof 20 locks it to ground through wipers a 31, and contacts 52, 42. On the operation of relay G0. a substitute circuit for relay PR is established extending over alternate contact 21, limb P, magnet 2, 1, a, s, (l -10, 34-30, 50-60, L', relay SR to battery. These circuit changes occur without relay PR permitting the retraction of its armature, and said relay is now dependent for its energizing circuit entirely upon the last traced circuit extending over the line limbs of the callin line. Attracted armature 18 of relay CO energizes relays LR and 22, whereupon the retraction of arground from wiper a through alternate contact 20 to the multiple private contacts 8 at the connectors, continuing them busy against incomi calls.

.At substation A, a dial 5 is provide having teeth adapted to vibrate the spring 3 when the 'dial' is rotated clockwise and then released, to be returned to normal by its associated spring. The magnet 2 is provided with an armature pawl 4 normally engaging a notch in disk 5' and holding it 5 against actuation. When the receiver is re moved to initiate a call, current will for the moment flow through magnet 2 through its attracted'armature to momentarily unlock dial 5. Instantly, however, armature 17 of relay LR removes ground from limb S of the line and magnet 2 denergizes, its pawl then holding dial 5 locked until the line has finally been selected, when the bridging of battery B at E across the limbs P and S of the line through relays PR and SR again energizes magnet 2 which withdraws tbe pawl to permit clockwise rota tion of dial 5 by hand. 'The subscriber A How tates the dial until two teeth have When the contact passed below spring 3, and releases it. The returning dial causes two openings at contact 3 and two deenergizations of relay PR at E, while relay SR remains energized by current flowing through its right winding, contacts 79, 77, 83, to ground. Each deenergization of relay PR transmits an impulse from ground through contacts 80, 71, 81, magnet 66 to battery, which magnet efi'ects two steps of disk 67 in the direction of the arrow, spring 69 engaging its alternate contact as before described. Thus on the first actuation of magnet 66, circuit may be traced from ground through contact 91, alternate contact 69, release relay RR to battery, which relay, by armature 87, locks over wire 63 to ground at contact 58. Circuit may now be traced from battery through interrupter 1, lower winding of magnet PM, alternate contacts 89, 69, normal contact 91 to ground. Successive actuations of magnet PM drive shaft p and wipers 97, 98, 99, and also arm 68 supporting spring 69 until said spring engages the notch. When this occurs, the wipers will be engaging the second set of contacts 100, 101, 102, connected with wipers d for the second thousand, and the shifting to normal of spring 69 opens the circuit of the lower winding of magnet PM so that the wipers come to rest. Thereupon circuit is traced from ground through normal contacts 91, 69, contact 81, shifted on the first primary step, normal contact 82, busy relay BR to battery, and said relay energizes, its armature 91 closing the circuit through magnet SM which receives generator impulses, stepping all the sets of secondary wipers step by step over their respective contact sets. On the first step, the shifting of contact 82 disconnects relay BR from its original energizing circuit so it thereafter depends for its continued energization upon current through alternate contacts 86, 95, contact 99-102, wiper d and successive engaged contacts 105 of busy second selector F, the private contacts of busy second selectors being characterized by a ground connection. 105 of an idle one is reached, however, it will be ungrounded, relay BR will be deenergized, and actuations of secondary magnet SM will cease.

Further, the retracmnn of armature 95 connects ground to the wiper d and'so to the multiple contacts 105 of theselected second selector, rendering it busy. It is assumed that the selected second selector of the second thousand is one shown at F in Fig. 1, Part 3. The calling subscriber now actuates dial 5 as before to cause two breaks at contact 3 and two resulting dei nergizations of relay PR are occasioned while relay SR remains operated, the locking circuit of the latter being now traced through contacts 93,

' over wire L and to ground through contact energizing relay 108 at F. Each denergization of relay PR transmits a current impulse from ground through contacts 80, 71, contacts 92, 97 -100, d103, L 107, magnet 124 to battery, ac-

tuating said magnet twice, whichsteps disk 125 two steps in the direction of the arrow, spring 127 riding upon the periphery of the disk. The closing of alternate contact 127 connects ground from 123 through release relay BB which relay operates and, by armature 113, looks over wire 106 and to ground at normal contact 95. Circuit may then be traced from battery, through constantly traveling interrupter I, lower windmg of magnet PM contact 115, alternate contact 127 to ground at normal contact 123, and magnet PM will receive actuations stepping shaft 31 the primary wipers and the springs upon arm 126 until spring 127 reengages the notch when wipers 128, 129, 130 will be engaging the second set of contacts 131, 132, 133, terminals of the wiper set f for connections to the second hundred of the second thousand. The opening of alternate contact 127 prevents further actuations of magnet PM and the closing of normal contact 127 operates busy relay BR by' current through contacts 109, 110, 127, 123, to ground. Relay BR attracts its armature 118, closing generator circuit for 9 secondary magnet SM which steps all the sets of primary wipers e, f, etc., step by step over their contacts untiL the wiper f engages an ungrounded, and so idle, private contact 136 of a connector of the selected group. While wiper f is passing over grounded, and so busy, contacts, relay BR remains operated. by current through alternate contacts 112, 119, 130-133, f to grounds on successive engaged contacts 136. The set of contacts 134, 135, 136, connected to wires L, L and 150, extending to con nector G, is assumed to be the idle contact set. When this is reached, the ungrounded condition of contact 136 deenergizes relay BB since its original energizing circuit was opened at contact 109 on the first step of the secondary wipers, and the retraction of armature 118 prevents further actuations of magnet SM while the retraction of 119 grounds the engaged multiple contacts 136, the wipers f, F, f being now at rest engaging the contacts leading to connector G. The calling subscriber now actuates dial 5 to cause two breaks in the line circuit, de-

PR twice, whereby two impulses are transmitted from ground through contacts 80, 71, conductors L L", to Gr, through 160, 151, magnet 195 to battery, actuating said magnet which advances disk 196 two steps in the direction of the arrow, spring 197 then riding on the periphery of the disk. The resulting connection of spring 199 to ground through 198, 197, operates release relay RR by current through normal contact 185, whereupon armature 184 looks said relay through contact 183 to ground over the private wire 150. Pulsatitns now flow from battery through constantly traveling interrupter 1, upper winding of primary magnet PM contact 187, contacts 199, 198, 197, to ground, and primary shaft is advanced step by step, moving the wipers and the arm 204, carrying spring 197 and its associated contacts, in the direction of the arrow until the notch in disk 197 is again engaged, when the shifting to normal of the spring 19? opens circuit through primary magnet PM and the primary wipers 207, 208, 209 rest engaging the second set of contacts 210, 211, 212, 'connected to wipers h, 11 71 having before them multiple contacts 6, 7-, 8, of lines numbered 2221 to 2229 inclusive, followed by contacts of line 2220, zero being ten im-- pulses. During the deenergizations of relay PR', relay SR remains operated by current flowing through its armature 79 and ing of said relay through normal contact 180, and contact 209212 and wiper [L3, to the multiple test contact 8 of the called line. The deelnergization of relay LO disconnects the right winding of relay TR from the original energizing ground connection and the relay now depends for its continued energization upon such connections as may exist at multiple contact 8.

Assuming first that the called line is idle, its contacts 8, as indicated, will be connected to the same side of battery to which the left winding of test relay TR is connected, so that said relay immediately de-i nergizes, when the closing of normal contact 166 operatesringing control relay RC by current from ground through said relay, contacts 162, 152, normal contact 166. contacts 180, 209212, k 8, 16. cut-off relay C0 of the called line to battery. The operation of said cut-ofi' relay opens the normal battery over wires L and L to ground, first at primary off-normal contact 157 and then through contact 198197 to ground. On the clcsing of normal contact 197 after the primary wipers are adjusted, circuit is traceable from ground through said normal contact, 191, 153, 156, locking relay L0 to battery, actuating said relay which, by contact 161, locks to ground through 165, 158, and, by armaturev160, shifts wire L from crnnection with magnet 195 to connecticn with magnet 200. when new the calling subscriber transmits the units digit 1, a single deenergixaticn of relay PR transmits an impulse as before from ground through wire L", said impulse now passing through alternate ccntact 160 and magnet 200 to battery, and said magnet advances disk 201 a step in the direction of the arrow, whereby spring 202 rests upon the periphery of the disk and engages its alternate contact. Such engagement energizes primary release relay lRR, which, by tll'll'ltv ture 192, looks to ground at contact 159, while its armature 1H0 closes a circuit from battery through constantly traveling interrupter 1 upper winding of 'magnet SM and alternate contact 202 to ground. so that magnet SM receives actuaticus until spring 202 overtakes the nctch in disk 201, when said spring shifts to normal to prevent further actuaticns of magnet Sal", at which time the secondary shaft 8 will have rotated sutliciently so that wipers II. in. II will be engaging the tirst contact set (1. T. 8. that of the called line 2221. ncrmal of spring 202 sends an impulse from grr uud through contacts 154. 163. right winding of test relay "IR. to battery. and said relay immcdiatelv energizes. opening contact 165 to de'inergi c lccking relay LO,

while armature 166 connects the left wind- The shifting from connections of the line and line relay LR and connects the line wires P and S to contacts 6, 7, thereby establishing the talking connections of the line circuit. By the closing of alternate contact20, the ground traced through relay RC to multiple contacts 8 is connected to the private contacts 11' at the line selectors, continuing said contacts unselectahle. The energization of relay RC connects constantly operating interrupter I with the so-called tlip-fiop relay FF and said relay alternately attracts and releases its armature, connecting and disconnecting ringing generator G with and from the called line. current from said generator passing over-limb S. through the call-bell and condenser at the substation Z, returning over P, alternate contact 21, and through impedance 173 to battery. As soon as the called subscriber answers and removes his receiver. hock-lever 1 closes a conductive circuit through the substation. and as soon as the armature of relay F1 is retracted, circuit may be traced from ground through answering relay AR, contact 175, armature 01 FF. contacts 20r-211. lat-7. alternate contact 10. S, 3, raised hook-lever 1. magnet 2. P, alternate contact 21, contacts 6 /L', 21020T. 17-1 and impedance 173 to battery. Attracted armature 178 of relay AR energizes closing relay CR which, by armature 170, looks to ground at 181 and, by armature 171, disconnects interrupter I from relay FF, so'that said relay remains inert and genffitor excluded from the called line. Attracted' al'matures 168, 169 now complete the talking circuit at the c nnector G. said talking circuit, as already stated,

being indicated throughout the circuit through the impedances of PR mite contacts 81, 72, with reversing relay RV and battery. whereby said relay be comes energizcd and reverses the connections of battery B to the calling line. Such reversal may be employed to operate any of the known polarized meter or pay station devices of the art. The calling and called substations are now connected for conversation, central battery talking current being supplied to substation A from battery B and SR, while current to called substaticn Z is supplied from the central battery through impedances 173 and relay All. the condensers 73, 7-lbeing interposed in the talking circuit at first selector l). The inductances of the magnets :5 serv as thc impedance coils customarily employed in the transmitter battery supply branch of thc substation talking circuits. \Vhen the vsubscribers finish their conversation, they replace their receivers. \Vhen subscriber Z d1 es so. connector ii alone restores to normal. \Vhen subscriber A. dccs so. line selector D, first selector F. and second selector F are all restored. Thus the replacing of the receiver at substati'cn Z deiinergizes ,relay AR and circuit is traced from battery through secondary release relay SRR, contacts 172, 179, to ground through contact 155. Armature locks relay SRR to ground at 155, and attracted armature 1S1 closes generator circuit through the lower winding of secondary magnet 3M and actuations of said. magnet will be produced until the secondary switch mechanism reaches normal, when the shifting of the secondary off-normal contacts will occasion the deenergization of relay SRR by the opening of contact and retracted armature 181 will prevent further actuations of magnet SM By suitable mechanical connections of secondary shaft 8 not only the secondary wipers and the springs carried by arm 203 are continued in their original direction of travel to a normal point, but the disk 201 is also rotated to normal. On the energization of relay SRR as described. its armature 183 opens the locking circuit of release relay RR and said relay deenergizes, circuit being then traced from the generator through the lower winding of magnet PM and contacts 190 and 188 to ground. lVhen magnet PM has been actuated a suiiicient number of times to bring: the primary wipers. arm 204 with its associated springs, and disk 196 to a normal point. the primary oil-normal PO ccntacts will be shifted to normal. the open ing of contact 159 de nergizing primary release relay PRR and retracted armature 190 will prevent further actuations of primary magnet PM and the primary switch mechanism will be at normal. As soon as the \ripcrs start their restoring travel, the circuit including relays RC and (O is opened nism is restored.

soon as both primary and both relays are de'e'nergized. As soon as relay SRR energized as described, the opening of normal contact 181 deenergized closing relay CR, whose retracted armatures 168 and 169 place the talking primary wipers on open circuit during release. It will be observed that during release, the wire 150. extending to private contacts at the seccnd selector, is held grounded over two branches, one extending through alternate contact 182. and the other through contact 193 and armature 188, so that, until both the primary and secondary mechanism of the connector is restored and relays SRR and PRB are both deiinergized, the connector is held bus at the second selector. \Vhen the calling subscriber A replaces his receiver, relays PR and SR at E both de energize. there being no ground at this time connected to locking contact 79 at relay SR. Circuit may now be traced from ground at I). through contact .4. wire 61, contacts 70, 78, wire 62, release relay HR, to battery. Relay RR, by its armature 56, locks to grounds at contacts 38 and 45, whereby said relay RR will remain energized until both the primary and secondary switch mecha- Attracted armature 53- energizes secondary relay SR by current iiownig to ground at contact 43, and said relay SR remains energized, holding closed at contact 51 the generator circuit for secondary magnet SM, until the secondary wipers reach normal and the opening 0 contact 43 deenergizes relay SR when, its armatures being retracted, further actuations of magnet SM are prevented. When relay RR energized, its attracted armature operated relay PR by current flowing to ground at contact 39. and said relay R by armature l7, closed the generator circuit of magnet PM, and the primary wipers are continued in the original direction of travel until they reach a normal point when the opening of contact 39 deenergizcs relay PR and, its armatures being retracted. further actuations of magnet PM are prevented. As

and secondary offnormal contacts are restored, relay RR has its circuit opened and de'energized. l pon the initial energization of relay RR. before described. attracted armature 57 operates rolay 37 and its armature SR ungrounds win 63, whereby release relay HR" at E is deenergized. On its denergization. rclay BR operates by current through retracted armature Rd to ground at contact 83. and attracted armature 9 closes generator circuit of magnet SM. which rotates the secondary wipers in the original direction t a normal point when the shifting of contact 83 dci nergizcs relay BR whose armature i l prevents further actuaticns of magnet SM and the secondary wipers rest at normal. Further, on the dei nergization of relay RR.

lllO

relay operates by current through normal contact 88 and contact 85 of the primary off-normal switch to ground. Armature 90 closes the generator circuit for the upper winding of magnet'PM and said magnet receives actuations, turning the primary wipers, arm 68 with its associated springs, and disk 67, in the original direction until a normal point is reached, when the primary off-normal contacts are restored, the opening of contact 85 preventing further actuations of magnet PM by causing the deenergization of relay 65. the mechanism of first selector E being then at normal. At masterswitch C, the private contact 28 of the switch pair DE is held grounded until both selectors have reached normal, ground being traced atl), through attracted armature 54,

and at E through attracted armatures 91 and 96, so that until the switch pair is fully restored, the wipers of the master-switch cannot come to rest upon the contacts of said switch pair. As soon as relay BR at E operat ed, attracted armature 95 removed ground from wire 106 extending to F, so that release relay BB at second selector F deenergized. Its armature 112 then operated busy relay BB by current to ground at alternate contact 108, and the resulting closing of contact 118 caused generator impulses,

through secondary magnet 'SM which turned the secondary wipers around to a normal point, at which time the shifting to normal of contact 108 deenergizes relay BR and its retracted armature 118 prevents further actuatio-ns of magnet SM Further,

on the deenergization of relay R13 relay 121 operated by current to ground at contact 111, and attracted armature 122 closed a generator circuit through the upper winding of magnet PM which receives actuations, turning the primary wipers, the arm 126 with its associated springs, and disk 125 around to a normal point, when the opening of contact 111 will deenergize relay 121 and second selector F will rest at normal, the opening .of contact 122 preventing further actuations of magnet PM During restoration, the multiple private contacts 103 or F are held grounded over wire 106, through alternate contacts 123and 120, so that until selector F is fully restored, its terminals at the first selectors E remain lousy.

Assuming that at the time test relay TR at G was operated to connect its left winding with Wiper h to test the called line, said line was busy, then the multiple contacts 8 would have been connected to ground in one of the several ways heretofore referred to and relay TR would have remained locked, holding the busy back machine I operatively connected to talking conductor L and the busy signal would be transmitted over the talking circuit to the calling substation A, where the calling subscriber, hearing it in his receiver, would replace the same upon the hookswitch to cause the restora' tion of selectors D, E and F as before described. Under the present circumstances, his act will also restore connector (l, since, as soon as relay BR at F operates, ground is removed from conductor 150 and release relay BR" will be decnergized. Since an swering relay AR has not operated, the closing of contact 186 will operate secondary relay SRR by current through normal contact 206 and to ground at contact 155, and the connector G will be automatically restored to normal in a manner which will be understood from the preceding description. As soon as the locking circuit of relay TR through contact 8 of the busy line is opened by the restorations of the wipers, the relay TR will be deenergized. It will be observed that when the called line is busy, the answering relay AR, the ringing control relay RC, and the closing relay (1% remain dcenergized. The reason why the calling subscriber cannot release the connector in the case that the called subscriber has answered,.is because at such time the armature 205 of relay AB is attracted, thus placing an additional ground upon the locklng armature 18 of release relay RR and rendering its de'cnergization solely dependent upon the position of the hook-lever at the called substation. The circuits are so arranged that if the calling subscriber 0perates part of the switches and then replaces his receiver without completing the connection, the operated switches will be restored to normal. For example, suppose that as soon as the first selector E is connected with the called line. the receiver is replaced. Relay PR deenergizes, but relay, SR does not immediately dee'nergize because of a locking circuit extending through contacts 79, 77, 83, to ground. The deenergization of relay PR accordingly transmits an impulse from ground through contacts 80 and 71, 81, and magnet 66' to battery, and said magnet advances disk 67 a step and the primary wipers initiate their travel and select the first group. lVhen this occurs, secondary travel is initiated in the usual ,manner and contact 83 of the secondary 0H- normal switch is shifted to its alternate position, opening the locking'circuit of relay SR, which deenergizes, closing the release circuit between wires 61 and 62 and the release of selectors D and E proceeds as before.

1f the calling sub criber bad operated first selector E to select second selector F and then replace his receiver. relay PR would del nergike and relay SH would not deencrgize. being locked over wire L" to ground at 108. .\u impulse will accordingly flow through contacts 80 and 7-1, over Wire L to magnet 124.

The second selector .F 3.;

would then select its first group of contacts and its secondary travel would be initiated in a manner obvious from the above paragraph, the opening of contact 108 then deenergizing relay blt to close the release circuit between wires 61 and (32.

1f the calling subscriber, after adjusting selectors E and F so that connection extended to connector (1, then replaces his re ceiver, the deenergization of relay PR will transmit an impulse over wires L and L to (it and through contacts 160, 151, to magnet 19.), relay 5R remaining locked over a circuit extending over wires L and L, first to ground at 157 and then to ground at contact 108-19T until spring 197 engages the notch in disk 196. When this occurs, locking relay LO will operate before relay SR allows its armatures to retract, and said relay will remain locked through contacts 101 and 177 to ground. Accordingly, current will flow over wire L, through alternate contact 160 and magnet 200 to battery, andthe connector G will select the first contact set of the first group. Then on the operation of test relay TR, relay L0 is deenergized, ground is removed from wire L, and release circuit between wires (31 and 62 at E is closed by the resulting de'encrgization of relay SR, and the disconnect operations proceed in a manner which will be understood from the preceding description, the removal of ground from wire 150 (when, in the course of the release, relay BR at -F energizes) opening the circuit of release relay BB so that the connector G also restores.

In constructing the system, the secondary off-normal contacts 83 at E, and 109 at F, are preferably arranged so as not to disengage their normal contacts until tbe respective secondary private Wipers have enaged their first contact set so as to insure tiat relays BR and BB do not deenergize on the first secondary step of their respective switches.

Referring now to Figs. 2 and 3, I there show, mechanism adapted more specifically for employment to perform the switching operations necessary for the primary wiper and control arrangements of a first selector, second selector or connector. For convenience, where applicable, reference characters corresponding to first selector E have been applied to Figs. 2 and 3. The primary wipers /r--/.: are insulatingly mounted upon the support 200, fastened to the rotary shaft 203, jrurnalcd at 203 to bridge 210, and at 20 1 to circular base-plate 211. The primary ratchet 212 is also fastened to the shaft 205 and adapted to be driven step by step by the armature-actuated pawl 208 of primary magnet PM. Said magnet is provided with two spools having the upper ends of their cores joined by a bridge of magnetic material 215, the transversely extending armature 214 being pivoted for reciprocating action between the polepieces 213 at the opposite or lower ends of the cores and provided with a retracting spring 214. The elements, which for convenience are indicated as wipers in Fig. 1, are represented by common strips in the mechanical drawing, as indicated, for example, at 99 in Fig. 3, the contacts 102 being placed adjacent to the common strip, the wipers k serving only to cross the said commons to uccessive con tacts when the wipers are rotated. Supported by a shaft 201, is also an arm 67, having at one extremity a buffer of insulating material normally engaging the spring (it) and holding it in engagement with its normal contact. The huo 202,to which is fastened the ratchet 201, fits loosely about the shaft 205 and is freely turned thereon, when actuations of magnet 66, which is similar in constructim to magnet PM, by armature-actuated pawl 200, drive the ratchet 201 step by step. Thus on the first actuation of magnet 00, the spring 69 will be brought forward. as viewed in Fig. 3, clear of the stud upon arm 67*, and said spring will, by its tension, free" its normal contact and engage its alternate contact.

Then when sufficient actuations of magnet PM are caused to drive ratchet 212 and shaft 205 to move the wipers and arm 67- until the buffer on the end of said arm engages spring 69, said spring will be shifted to normal and the mechanism will have oper ated the spring 09 in the manner required by the circuit I). Then, when later actuations of magnet PM are caused to rotate the wipers to a normal point, the stud 20? upon the left end of arm 67, which engages the alternate contact of spring 69 whenever the buffer on arm 67 engages said spring 60. will move the hub 202 and its spring 69 with its contacts around to a normal point.

In Fig. 4, is illustrated diagrammatically the preferred arrangements of the primary contact mechanism. As indicated in Fig. 2, the contacts are mounted in a circular bank, insulatingly heldbetween ring 209 and circular base-plate 211. The wipers of Fig. 1 are represented by the segments 97, 98 and 99, having adiacent to them their respective ten contacts 100, 101, 102, the latter contacts 102 being made somewhat broader than the line contacts 100 and 101, so that the segment 09, representing the wiper of Fig. 1, will be connected to a succeeding contact 102 beforeleaving the one to which it was previously connected. The wipers Ir, of which there are ten, supported by the piece 206 on shaft 205, and which extend at angles of thirty-six degrees, have no circuit connections in themselves, but serve only to cross the commons 97, 98 and 99 to successive associated contacts as the wipers are moved step by step. make pri iary otl normal contacts of Fig. 1, Part. 2. l he normal positions of the wipers I." For a complete operation and restoration to normal of the pi nuary switch mechanism, it is therefore onh necessary to move the wipers over the pace occupied by one common or segment. 'lhus, if the lii'th contact sci. loo, lol, luz, is to be selected, lire steps of the eipcrs ll: will be produced by magnet PM; and when the release is caused, six additional steps will bring them to a. normal point.

For the secondary switch mechanism of a first selector .1, a device, having driving mechanism like that illustrated in Figs. 2 and 3, may be employed. 1] such case, howevcr, the magnet 66 and its associated ratchet wheel 201, the hub Q02, and spring 69 with its contacts, are omitted. The contact. arrangement of the secondary mechanism will, however, differ from that employed for the primary selector mechanism. As indicated in 8, the piece 206, fastened to shaft 203, will support four superposed and insulatingly mounted wiper sets m, n, o and 7. The contact bank is circularly arranged, as before, and the ten sets of secondary wipers will be represented by ten sets of segments 0, d, etc., arranged in a circle, each having its appropriate ten contacts 103 placed adjacent to it. In Fig. 5, is indicated the arrangement employed for the talking contacts 103 and 104, and the associated common contacts 0 or c, d or d. The commons c, (i, etc, and their contacts form the top level of the circular contact bank and are crossed when the switch is operated by wipers m, and that the next level below will be composed of the commons c, (1', etc, and theirassociated talking contacts 1 crossed by wipers 11.. Below the two circular levels of talking commons and contacts, are placed the private commons c, d, indicated in F 6, with their associated contacts105 made broader than the talking contacts and crossed by wipers 0. Underneath the private commons and contacts, are placed the olf norma'l strips and contacts as indicated in Fig. 7, the operation of the break and make contact 81, of the break and mak contact, 83, and of the break contact 82, by the wipers moving away from thei normal "interrgroup positions, being sufficiently obvious. As in the case of the primary wiper mechanism. a complete operation and restoration to normal of the secondary switch is obtained by movinglhe wipers a total of eleven steps and so from one normal position to the next normal position.

The primary switch and its associated secondary switch are preferably mounted adjacent to each other, and short wires are At Stand 85, are indicated the two are the intersegmental, as shown.

employed to connect the respective contact sets 100, 101, 1012, in the primary switch, with the appropriate commons in the bank of the adjacent secondary switch.

it will be understood that the term selector, as applied to mechanism of the described character, is used as referring to a primary switch and its associated secondary switch as a unit.

For the second selector F, switch devices like those just described will obviously be employed. For the connector G, the primary switch will be like that already de scribed, the spring arrangement indicated at 197, 198, 199 being, of course, supplied. The secondary switch mechanism of the connector will be like that just described, except i that it will have added"toit the hub 202 shown in Fig. 3, with the proper magnet to drive the same and associated spring contacts indicated at G.

For the line selector D, the secondary switch mechanism will he like that described for switch F, and the primary mechanism will be the same as that indicated in F 3 and 4, except that there will be an additional wiper common over those indicated in Fig. 4: and its associated contacts to serve the purpose of the group selecting wiper of Fig. 1. For the line selector, the hub 202, its associated mechanism, and its ratchet and magnetare superfluous and may be omitted.

In adapting the switch mechanism described for the various switches, the primary and secondary otl-normal spring combinations indicated in the circuit diagram will, of course, be provided.

Obviously, modifications may he made. in the circuits and mechanisms employed with out departing from the substance of the invention.

I claim as my invention 1. A selector for automatic systems including a traveling switch corftrolling member adjustable responsive to directive impulses, an"auxiliary.switch member traveling when said first member travels, and controlling' means for automatically transmitting a secondary impulse after adjustment of said first member is completed.

' 2. A selector for automatic systems including a traveling switch controlling member adjustable responsive to directive impulses, switch wipers and adjusting mechanism to move's iid wipers, and means for stopping said wipers when said mechanism engages said member, whereby'the extent ,of adjustment of the latter controls that of the former, such engagement also serving to automatically transmit a secondary impulse.

3. A selector for automatic systems in eluding a traveling switch cont: oiling membcr adjustable responsive to directive impulses, switch wipers and adjusting mocha-- nism to move said wipers, means effective on vi (J initiation of travel of said member to cause operation of said adjusting mechanism whereby said mechanism overtakes said member after adjustment of the latter is completed, and an auxiliary selector circuit having its connections automatically changed responsi e to such overtaking.

-l. A connector for automatic systems including a traveling switch controlling member adjustable res 'ionsive to directive iIn pulses, an auxiliary switch member traveling when said first member travels and temporaril coordinated therewith, and a test relay hav ng its electrical condition altered when travel of both members is completed by c0- operative action between said members.

A connector for automatic systems Inclhding a traveling switch controlling member adjustable responsive to directive impulses. an auxiliary switch member traveling" when said first member travels and temporarily coordinated therewith, and a test relay controlled by joint action of said menil'iers.

(S. 3. connector for automatic systems including a traveling switch controlling member adjustable responsive to directive impulses. terminal selecting traveling contacts for said connector and normally at rest adjusting mechanism for moving said contacts, and means for stopping said contacts when said :nccl'ianism engages said member.

7. i l. connector for automatic systems including a traveling switch controlling member adjustable responsive to directive impuls terminal selecting traveling contacts for said connector and adjusting mechanism for moving said contacts. means for stopping said contacts when said mechanism engages said member. and a test relay having its electrical condition altered responsive to such engagement.

A. connector for automatic systems in- \';luding a traveling switch controlling memoer adjustable responsive to directive impulses. an auxiliary switch member traveling when said first member travels and temporarilv coordinated therewith, and a switch operated by joint action of said members.

5?. .& mnnector for automatic systems inclnd an impulse transmitting conductor, a primary switch controlling member adjusted responsive to impuls s over said conductor, traveling contacts for said connec tor and adjusting mechanism for moving said contacts, a secondary switch controlling magnet for said connector. and a switch cooperatively controlled by said member and said mechanism for connecting said magnet with said conductor.

l0. i connector for automatic systems including an impulse transmitting COIltltlCtOI, a primary switch controlling member adjusted responsive to impulses over said conductor, traveling contacts for said connector and adjusting mechanism for moving said contacts, a secondary switch controlling magnet for said connector, means for step ping said contacts when said mechanism engages said member, and means responsive to said engagement to connect said magnet with said conductor.

11. A connector for automatic systems including an impulse transmittii'ig conductor, a primary switch controlling member adjusted responsive to impulses over said conductor, traveling contacts for said connector and adjusting mechanism for moving said contacts, controlled by said member, and a switch controlled by joint action of said member and said mechanism to alter the connections of said conductor.

12. An automatic telephone system including a selector having a traveling switch device adjusted responsive to directive impulses, terminal selecting contacts and mechanism for adjusting said contacts operating simultaneously with said device, and appa ratus adjusted by said mechanism to overtake said device after the latters adjustment is completed.

13. An automatic telephone system including a selector having a traveling switch device adjusted responsive to directive impulses, terminal selecting contacts and mechanism for adjusting said contacts operating simultaneously with said device, apparatus adjusted by said mechanism to overtake said device after the latters adjustment is completed, and a circuit changing contact shifted by such overtaking.

14. An automatic telephone system including a selector having a traveling switch device adjusted responsive to directive impulses, terminal selecting contacts and mechanism for adjusting said contacts operating simultaneously With said device, apparatus adjusted by said mechanism to overtake said device after the latters adjustment is completed. a busy relay, and circuit connections altered responsive to such overtaking to alter the electrical condition of said relay.

15. A selector for automatic systems ineluding contacts arranged in groups, a device adjusted responsive to directive impulses to determine selection of the group, automatically operating mechanism adapted to pursue said device and overtake the same after its adjustment is completed, apparatus for controlling automatic selection of acontact set of the selected group, and means solely controlled by such overtaking to set said apparatus in operation.

10. A selector for automatic systems including contacts arran ed in groups, a device adjusted responsive to directive im' pulses to determine selection of the group, automatically operating mechanism adapted to pursue said device and overtake the same after its adjustment is completed, and means to opposite sides of said circuit adapted to be energized when the circuit is closed, a locking circuit for holding one of said relays energized while the other vibrates its armature responsive to the directive interruptions, and selector mechanism responsive to a prolonged interruption of said. metallic circuit to open said locking circuit whereby said locking relay dei nergizes.

18. A telephone system including a selector having a metallic circuit, a calling device for causing directive impulse interruptions in said circuit, a paiiuof relays bridged to opposite sides of said circuit adapted to be energized when the circuit is closed, a locking circuit for holding one of said relays energized, while the other vibrates its armature responsive to the directive interruptions, selector mechanism re sponsive to a prolonged interruption of said I metallic circuit to open said locking circuit whereby said locking relay denergizes, and a release circuit closed by such deie'nergization.

19.'A telephone system including a selector connected with a calling telephone line, a pair of relays held energized by current over said line, one of said relays having in addition a local locking circuit, means whereby the opening of the line circuit causes travel of said selector, and a switch device operated by such travel to open the locking circuit, whereby said relay having said circuit becomes dependent for continued cnergization upon the line circuit,

20. A telephone system including a se lector connected with a calling telephone line, a pair of relays held energized by cur rent over said line, one of said relays having in addition a local lockin circuit, means whereby the opening of the line circuit causes travel of said selector, a switch device operated by such travel to open the locking circuit whereby said relay having said circuit becomes dependent for continued energization upon the line circuit, and a release circuit jointly controlled by said relays.

21. A telephone system including a tele phone line connecting a substation with the exchange, a selector connected with said line at the exchange adapted for primary and secondary travel, circuit connections effective when the receiver is replaced at said substation to cause first primary and thereafter secondary travel or said selector, and a release circuit closed responsive to initia tion of secondary travel while the receiver is replaced.

mean

at the exchange adapted for primary and secondary travel, a normally closed off-normal contact for said selector, and means whereby the opened condition of said contact, while the line circuit is open, will restore said selector.

24. A telephone system comprising an automatic switch, means for transmitting cur rent impulses ,from a control point, a starting device for said switch mechanically as sociated therewith set by said impulses in a position dependent upon the number of impulses transmitted, and step-oyster; driving mechanism for advancing said switch to a position dependent upon the position at which said starting device set.

25. A telephone system comprising an au tomatic switch capable of primary and secondary adjustments, means for transmitting current impulses from a control point, a starting device for said switch set by said impulses in a position dependent upon the number A of impulses transmitted, means actuated thereby to adjust said switch to a primary position dependent upon the position at which said starting device is set, and means dependent upon the position of said starting device for giving said switch its secondary adjustment.

A telephone systeui comprising an automatic switch. means for transmitting can no rent impulses from a control point, a starting device for said switch having a member set by said impulses in a position dependent upon the number of impulses transmitted and a following member for following and 115 overtaking said first member in response to the advance ofsaid switch. and means for starting the advance of said switch upon the initial movement of said first member" and discontinuing it only when said follow- 12'" current impulses from a controhpoint, a 125 starting device for said switch having a member set by said impulses in a position dependent upon the number of impulses transmitted and a following member for fol lowing and overtaking said first member 111 13%! response to the primary adjustment of said switch, means for starting the primary adjustment of the switch upon the initial movement of said first member and discontinuing it only when said following member hasovertaken said first member, and means for starting the secondary adjustment of said switch as soon as said following member overtakes said first member.

28. A telephone system comprising an automatic switch 'capable of primary and secondary adjustments, means for transmitting primary and secondary current impulses from a control point. a primary starting device for said switch set by said primary impulses in a position dependent upon the number of primary impulses transmitted, means actuated thereby to adjust said switch to a primary position dependent upon the position at which said primary starting device is set, a secondary starting device for said switch set by said secondary impulses in a position dependent upon the number of secondary impulses transmitted, and means -actuated thereby to adjust said switch to a Secondary position dependent upon the position at which said secondary starting device is set.

29. A telephone system comprising an au tomatic switch capable of primary and secondary adjustments, means for transmitting primary and secondary impulses from a control point, a primary starting device for said switch having two members, the first member set by said primary impulses in a position dependent upon the number of primary impulses transmitted and the second member for following and overtaking the first member in response to the primary adjustment of said switch. means for starting the primary adjustment of said switch upon the initial movement of said first membe' and discontinuing it only when said second member overtakes said first member, a secondary starting device for said switch having two members, the first member set by said secondid'y impulses in a position dependent upon the number of secondary impulses transmitted and thesecond membeni'or following and overtaking said first member in :response to the secondary adjustment of said switch, and means for starting the secondary adjustment of said switch upon the initial movement of the first member of said secondary starting device and disc'ontinuing said adjustment only when it is overtaken by its second member.

.30. A telephone system comprising an automatic switch capable of'primary and secondary adjustments, means for transmitting primary and secondary current impulses from a control point, means responsive to said primary impulses to give said switch a primary adjustment, a starting device for said switch set by said secondary impulses in a position dependent upon the number of secondary impulses transmitted, and means actuated thereby to adjust said switch to a secondary position dependent upon the position at which said starting device is set.

31. A telephone system comprising an automatic switch capable of primary and secondary adjustments, means for transmitting primary and secondary current impulses from a control point, means responsive to said primary impulses to give said switch a primary adjustment, a starting device for said switch having a member set by said secondary impulses in a position dependent upon the number of secondary impulses transmitted and a following member for following and overtaking said first-mentioned member in response to the SECOIldtlly' adjust ment of said switch, and means for starting the secondary adjustment of said switch upon the initial moven'icnt of said first-menr tioned member and discontinuing said adjustment only when said following member overtakes said first-mentioned member.

32. A telephone system comprising a tele phone line, a pair of relays at the exchange connected with said line, a selective switch, an armature for one of said relays serving to adjust said switch and adapted to vibrate responsive to circuitchanges produced in said telephone line, a maintaining circuit for the second relay held closed while said armature vibrates, a release circuit for said selective switch controlled by said second rclay, and means operating upon a prolonged retracticn of said armature to deenergize said second relay.

33. A telephone system comprising an automatic switch, a starting device for said switch mechanically associated therewith and adapted to be set in any one of a plurality of positions, a substation telephone line connected to said switch and means controlled thcreat for setting said starting device, and means for advancing said switch to mechanically cooperate with said setting device whereby said switch is stoppcd in a position dependent upon the position at which said starting device is set.

34. A telephone system comprising a selector switch connected with a calling line, a pair of relays held energized by current over the calling line, means whereby the opening of the line circuit causes travel of said selector. to extend the circuit of the calling line, means for establishing a locking circuit for one of said'relays, effective during such travel, said relay then being dependent for energization upon the line circuits, and a release circuit controlled by said relay.

35. A telephone system including a selector switch connected with a calling line, connector switches adapted to be connected with by said selector, a pair of relays held energized by current over said line, one of said relays having an additional local looking circuit, means for opening the line circuit whereby one of said relays is operated,

means responsive to the operations of said relay to cause travel of said selector to connect with a cohnector switch, a switch device operated responsive to such travel to open said locking circuit, whereby said relay having said circuit again becomes dependent for energization upon the line circuit, a second locking circuit for said relay established from said connector responsive to connection therewith. said second locking circuit being adapted to be interrupted responsive to operation of the connector switch, whereby said locking relay becomes dependent for continued energization upon the line circuit, and a release circuit, for said selector controlled by said locking relay.

36. A selector switch for telephone systems, having bank contacts divided into groups, wiper COUtflCh for cooperation therewith, electromagnetic mechanism for operating said wiper contacts, switch contacts adapted to he moved to a position corresponding to a group of said contacts, and operated responsive to such movement, a control circuit for said mechanism rendered etlective responsi e to such operation of the switch contacts, to cause said mechanism to move said wiper contacts to a selected group, whereby said switch contacts are adapted to be operated by said mechanism to 'render said control circuit ineffective- 37. A telephone system comprising a selector switch connected with a calling line. connector switches adapted to be connected to by said selector, a pair of relays held energized by current over said line, one of said relays having an additional local look ing circuit. means whercbv the opening of the line circuit operates the other of said relays, means responsive to such operation of said other relay to c'ause travel of said selector to connect with a'connector switch, a switch device operated responsive to such travel to open said locking circuit, whereby said relay again becomes dependent for encrgization upon the line circuit, and a second local locking circuit for said relay established from said connector responsive to connection thereto.

38. A telephone system comprising a selector switch connected with a calling line, selector switches adapted to be connected to by said selector, a pair of relays held energizedby current over said line, one of said relays having an additional local lockin circuit, means whereby the opening of the line circuit operates the other of said relays, means responsive to other relay to cause travel of said selector to connect with one of said selector switches, a switch device operated responsive to such travel to open said. locking circuit, whereby switch for telephone such operation of said said relay again becomes dependent for energization upon the line circuit, and a second locking circuit for said relay established from said selector responsive to connection thereto.

39. A selector switch comprising groups of contacts and coiiperating wiper mechanism, a controlling member and means for moving said mcniber to any one of a plurality of positions corresponding to said groups of contacts, means for moving said wiper mechanism into stopping engagement with said member when moved to one of such' positions, wherehy the corresponding group of contacts is selected, and means for thereafter operating said wiper mechanism to select a contact in the selected group.

40. A selector switch comprising groups of contacts and coiiperating wiper and step-hystep driving mechanism, a control member having switch contacts for, controlling said driving mechanism, means for moving said member to a position corresponding to a. desired group of contacts, means for automatically stopping said driving and wiper mechanism to engage and operate said switch contacts to stop said driving mechanism.

41, A telephone system comprising a selector switch, trunk lines leading therefrom, a normally open metallic circuit telephone line connected to said switch, a pair of relays and means for energizing same responsive to closing of said metallic circuit, meansfor causing interruptions of said circuit, one of said relays vibrating its armature responsive thereto, a local locking circuit for the other one of said relays effective during such in terruptions, means for operating said switch responsive to the vibrations of said first relav and a release circuit for said switch colitrolled through contacts of said second relay.

42. A selector switch for telephone systems" comprising a primary relay, a second relay, {1 control circuit whereby said relays are energized, means for rapidly interruptmg the control circuit whereby said primary relay; is correspondingly operated for transmitting primary impulses, a local locking circuit for said second relay efiective during such primary operations, means for cperat ing said switch responsive to said primary impulses, means for deenergizing said second relay only responsive to a prolon ed in terruption of the control circuit, an a release circuit for said switch controlled by said second relay.

43. A primary 1 and secondary selector systems comprising a primary relay, a second relay, a control circuit ,Whereby said relays are energized, means for rapidly interrupting the control circuit whereby said primary relay is cur respondingly operated for transmitting pri mary impulses, a local locking circuit for said second relay efi'ective during such pri- 

